Oxo-biodegradable Plastics in Aqueous Media

Discarded plastics are a serious problem in freshwater as well as marine environments. The difficulties in addressing this situation include the complexities of identifying the origins of this pollution and the variety of plastics involved. Alleviation of these problems can occur for those items that are or could be made from polyolefins. If these products are made from TDPA® -based oxo-biodegradable polyolefins, then the combination of heat, sunlight and mechanical stress in the environment will result in the oxidation of the material and bioconversion of the oxidation products. Since PE and PP have specific gravities lower than water, these materials will float and be exposed to UV radiation (sunlight) and heat; degradation and disintegration with drastic molar mass reduction will occur.

Chiellini et al. prepared thermally oxidized LDPE containing TDPA® with acetone-extracted fractions that were even more highly oxidized. These were exposed to microflora present in river water. Biodegradation was assessed by monitoring carbon dioxide generated in a respirometer. Levels of biodegradation up to 12% and 48% for the oxidized fragments and the corresponding acetone-soluble fractions were measured over a 100-day time frame.